Recently, an image processing apparatus to perform an image processing of digital image data has been applied in copying machines, facsimiles, printers, scanners and so forth. In the above-described image processing apparatuses, image data are required to be processed more rapidly and for this purpose, the apparatuses have in recent years started to include hardware such as an Application Specified Integrated Circuit (ASIC).
When image data containing both a portion represented in dots such as pictures or photographs, for example, and another portion represented in line such as characters, for example, are output to a print medium, some measures need to be taken to eliminate moiré, for example for pictures and pattern portion so as to refine image quality and also some other measures need to be taken for characters, such as a clarification process, for example.
In order to automatically perform the above-described processes in compliance with respective image data, an image-area separation technology is known to automatically image-separate picture and pattern portions, respectively. Published Japanese Patent Application Laid-Open Publication No. 2777378 discloses the above-described image processing apparatus.
It is also well known that although different figures and different characters of image data have different attributes according to different pixels, respectively. The attributes of the pixels that are aligned adjacent tend to influence to each other to become nearly identical images. It is desired that the discrimination result associated with attributes be an area that has a dimension large enough to some extent so that the discrimination result allows the image data to be easily determined. Published Japanese Patent Laid-Open Publication No. 3256267 describes a technology in which to accurately obtain the character area from surrounding pixels when a pixel has been determined as a character, the pixels surrounding a pixel of interest is also easily determined as a character in accordance with the weight or probability with respect to the distance between the pixel which has been determined as a character and a specified pixel.
However, in conventional image processing apparatuses, a plurality of circuits may be pre-mounted or an ASIC may be exchanged when the contents of image processing data are required to be replaced, thus making it difficult to change the contents of the image processing apparatus with flexibility. It may also be considered an alternative to perform an image processing by changing software configuration using general-purpose microprocessors. However, this method has also a defect in that it takes a large amount of time to process data.